Pat the 2 steaks dry with paper towels and season both sides with salt and pepper.
Heat a large frying pan over high heat until very hot. Add the steaks (do not overcrowd; cook in two batches if the pan is too small). Cook, flipping once, until desired doneness (for reference, about 3–5 minutes per side for medium-rare depending on thickness, or cook to your preferred internal temperature).
Transfer the cooked steaks to a plate, tent loosely with foil, and let rest while you finish the aromatics.
In a separate pan, heat 1/4 cup olive oil over medium-low. Immediately add the 6 thinly sliced cloves of garlic and the 6 sprigs of rosemary. Cook gently, stirring or swirling the pan and watching carefully so the garlic does not burn.
When the edges of the garlic turn light brown, use tongs to add the rested steaks back into the pan, nestling them among the garlic and rosemary. Flip the steaks once so both sides are coated, and season again with salt and pepper if desired.
Remove the steaks to a serving platter and pour the garlic, rosemary, and olive oil from the pan over the steaks. Serve.